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Technical Support / Re: strange ticking sound under the bed in our 2008 Beaver Patriot Thunder
« Last post by Eric Maclean Co-Admin on January 06, 2026, 01:59:28 PM »Ante
I'm not familiar with the lay out of your coach IE what's under the bed I assume you have a double slide coach with a bed slide .
a little bit more information might help us determine what might be the origin of your noise.
You stated it may be related to your battery and inverter problems.
At what frequency does the clicking happen is it constant or intermittent do you have a solar set up.
What you may be hearing is the big boy solenoid cutting in and out this sometimes happens in systems setup with a solar array.
Let me explain
The big boy is used to combine you two battery banks ( chassis and house ) for charging purposes or to provide a battery boost while starting the coach via the boost switch at the drivers station.
The big boy solenoid is controlled by a small electronic box called a B.I.R.D or bidirectional isolator relay delay to achieve the charging function
In short what the bird does is monitor the voltage of each battery bank separately and when it sees that one bank or the other is receiving a charge voltage above a preset voltage approx 13.2 volts it commands the big boy solenoid to operate connecting the two battery banks together and following them to be charged as one battery bank by the available charging source weather that was the inverter or solar on the house battery side or the engines alternator on the chassis battery side.
This system is reliant on the bird seeing a good charge voltage of approx 13.2 volts or more for a more than a set period of time let's say two minutes this is to allow the charging system to stabilize and to avoid the solenoid from opening and closing repeatedly.
The problem comes when one battery bank is heavily discharge ( in this case likely the chassis bank ) in this case the bird does what is supposed to and connects the two battery banks to charge then as one but if the one bank is heavily discharged this causes the charge voltage to be drawn down below the preset 13.2 volt threshold and the bird then allows the big boy to drop out as it no longer recognizes a viable charge voltage.
Of course at this time the charge voltage is still present on the house battery bank and without the extra draw from the chassis bank the voltage jumps back up to an acceptable charge voltage 13.2 volts or more and the bird then commands the big boy to close again connecting the two battery banks and the cycle continues.
This is common in a system using a solar array because often the solar array will provide a marginal charge voltage depending on the amount of sun it's getting .
You may also what to check the operation of the Big Boy solenoid as they are known to develop dirty contacts inside them .
There is an article in the COMMON PROBLEMS section on how to disassemble and clean the contacts in the big boy.
For further information on the BIRD and the big boy service go to the COMMON PROBLEMS articles in the coach assist library.
The bird article has a good description and troubleshooting section .
Sorry for going on so long
As always have a great day
Eric
I'm not familiar with the lay out of your coach IE what's under the bed I assume you have a double slide coach with a bed slide .
a little bit more information might help us determine what might be the origin of your noise.
You stated it may be related to your battery and inverter problems.
At what frequency does the clicking happen is it constant or intermittent do you have a solar set up.
What you may be hearing is the big boy solenoid cutting in and out this sometimes happens in systems setup with a solar array.
Let me explain
The big boy is used to combine you two battery banks ( chassis and house ) for charging purposes or to provide a battery boost while starting the coach via the boost switch at the drivers station.
The big boy solenoid is controlled by a small electronic box called a B.I.R.D or bidirectional isolator relay delay to achieve the charging function
In short what the bird does is monitor the voltage of each battery bank separately and when it sees that one bank or the other is receiving a charge voltage above a preset voltage approx 13.2 volts it commands the big boy solenoid to operate connecting the two battery banks together and following them to be charged as one battery bank by the available charging source weather that was the inverter or solar on the house battery side or the engines alternator on the chassis battery side.
This system is reliant on the bird seeing a good charge voltage of approx 13.2 volts or more for a more than a set period of time let's say two minutes this is to allow the charging system to stabilize and to avoid the solenoid from opening and closing repeatedly.
The problem comes when one battery bank is heavily discharge ( in this case likely the chassis bank ) in this case the bird does what is supposed to and connects the two battery banks to charge then as one but if the one bank is heavily discharged this causes the charge voltage to be drawn down below the preset 13.2 volt threshold and the bird then allows the big boy to drop out as it no longer recognizes a viable charge voltage.
Of course at this time the charge voltage is still present on the house battery bank and without the extra draw from the chassis bank the voltage jumps back up to an acceptable charge voltage 13.2 volts or more and the bird then commands the big boy to close again connecting the two battery banks and the cycle continues.
This is common in a system using a solar array because often the solar array will provide a marginal charge voltage depending on the amount of sun it's getting .
You may also what to check the operation of the Big Boy solenoid as they are known to develop dirty contacts inside them .
There is an article in the COMMON PROBLEMS section on how to disassemble and clean the contacts in the big boy.
For further information on the BIRD and the big boy service go to the COMMON PROBLEMS articles in the coach assist library.
The bird article has a good description and troubleshooting section .
Sorry for going on so long
As always have a great day
Eric